Literature and Art 



Lesson 1 1 5 



VENTILATION 



How is the air in this room heated ? 

 Place a thermometer near the floor. Tie another to 

 the end of a window pole and put it near the ceiling. 

 What does each thermometer tell about the heat? 

 In what direction does the heated air seem to move ? 

 Where do you think fresh air comes in ? 

 Tell about all the ways you know for ventilating rooms'. 



SUGGESTED WORK 



Fan yourself with a piece of stiff paper or cardboard. Tell what'you feel. 



Place some bits of paper or feathers on the desk. Fan them, but do not 

 touch them. What causes them to move? What is the moving power called? 



Breathe into a glass containing lime water. Tell what change takes place 

 in the appearance of the water. This is because the air we breathe into the 

 water is not pure. It is not good for us to breathe the same air over and over, 

 so the air in our rooms should be changed often. Where should an opening 

 be made to let the foul air out of the room ? 



Lesson 116 



THE WIND'S WORK 



Mention things that you have seen moved by the wind. 



What work is done by the windmills ? 



How does the wind sometimes help people to travel ? 



What happens when a high wind 

 blows over a body of water ? 



What do these things tell 

 about the wind's strength? 



Make pictures or cuttings of 

 things that tell you the direction 

 from which the zuind is blowing. 



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